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53 Cards in this Set
- Front
- Back
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What are the differentials for pruritic skin disease?
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Most common
- Hypersensitivities (FBH, Atopic derm and AFR) - External parasites (sarcoptes) Secondary - Superficial bacterial infection - Malassezia (yeast) dermatitis Occasional - Demodicosis - Dermatophytosis - Pemphigus foliaceus |
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What are the differentials for alopecic skin disease?
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Most common
- Demodex - Dermatophytosis - Endocrine (hypoT, hyperT, hyperA, sex hormones) - Superficial bacterial pyoderma - Hypersensitivities Less common - Hair follicle diseases - Paraneoplastic syndromes |
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What diseases are likely to be bilaterally symmetrical?
What diseases are likely to be assymetrical ? |
Bilaterally
- Endocrinopathies - Hypersensitivities Unilateral - SBP - Demodex - Dermatophytes |
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What are the most common nodular skin diseases with swelling and/or discharge?
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Most common
- Deep bacterial infection - Demodicosis Less common - Neoplasia Rare - Unusual bacterial infections (e.g. nocardia, mycobacteria etc) - Deep fungal infections - Sterile granulomatous/pyogranulomatous diseases |
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Discuss deep bacteria pyoderma.
What is it? Who is it common and rare in? |
It is a secondary disease - usually an extension form SBP
Common in dogs Rare in cats |
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What are the different forms of DBP?
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Localised
1. Nasal (long nosed breeds) 2. Muzzle, chin, lips (short coated breeds) 3. Pedal (feet) 4. Pressure point 5. Acral lick furunculosis 6. Pyotraumatic dermatitis (hot spots) German shepherd form - T cell deficiency Regional form |
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How do you diagnose DBP?
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Cytology (impression smear, FNA)
- Neutros - Macros - Intracellular bacteria (cocci mostly, rods, may be SPARSE) Bacterial culture important with - chronic, poorly responsive cases - if you see rods on cytology - if you have poor initial response to empirical therapy |
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How do you treat DBP?
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1. Systemic antibiotics
- Amoxyclav (or based on culture) - 6-12 weeks minimum 2. Antibacterial soaks/shampoos/topical lotions - e.g. chlorhexidine 3. Treat underlying disease!! |
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What is the prognosis for DBP?
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- Good for short term response
- Poor if you do not address underlying cause (recurrence likely) |
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What can look quite similar to DBP?
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Demodicosis
Review this in other cards... |
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What are the clinical lesions for 'unusual bacterial/fungal infections?
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- Nodules and draining tracts
- Maybe tissues grains - Often solitary and well-demarcated |
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What bacterial and fungal causes are there of the unusual infections?
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Bacterial
- Mycobacteria - Actinomyces (nocardia...rare) - Bacterial pseudomycetoma - staph (rare) Fungal - Cryptoococcosis (cats common on nose... dogs, common on skin and systemically) - Other environmental fungi - Dermatophytic pseudomycetoma |
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How do you diagnose unusual infections ?
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1. Cytology
- Impression smear/exudative smear - Diff quik stian +/- gram stain 2. Culture and sensitivity - FNA and tissue biopsy 3. Biopsy for histopath - Special stains |
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How do you treat unusual infections?
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- Surgical excision and debulking
- Long course of antibiotics and antifungals |
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What are some examples of sterile nodular diseases?
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1. Sterile granuloma/pyogranuloma syndrome (nose, trunk, not painful)
2. Histiocytosis (trunk, not painful) 3. Sterile panniculitis (ventral abd, multifocal, poorly demarcated swelling) 4. Juvenile cellulitis (puppy strangles, face and pinnae, SPECTACULAR lymphadenomegaly and malaise... dogs only, typically 3-6months but up to 14months, sometimes pruritic) |
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How do you diagnose sterile nodular skin diseases?
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Via exclusion of infectious causes.
1. Cytology - Impression smear/exudative smear - Diff quik stain and gram stain - Absence of organisms 2. Histopath - Special stains 3. Bacterial and fungal culture - FNA, tissue biopsy... should be no growth |
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How do you treat sterile nodular skin diseases?
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Juvenile cellulitis
- Prednisolone (complete resolution) Immunosuppressive treatment - Niacinamide (VitB), doxy +/- prednisolone |
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What are the different neoplasias we see on the skin?
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1. Sebaceous gland hyperplasia or adenoma
- Common in dogs - Multiply - Often called warts 2. Basal cell tumours - Benign (uncommon in cats) - Carcinomas (common in cats, uncommon in dogs) 3. Melanoma - Typically benign in dogs 4. Papilloma - Rare - Mostly multiple - In young or immunocompromised animals 5. Lipoma - Very common 6. Histiocytoma - Common - benign - self-resolving 7. Mast cell tumours - Common - May be generalised + papular occassionally - Often aggressive 8. Haemangioma, haemangiosarcoma 9. Hair follicle and sweat gland tumours 10. Fibroma/sarcoma |
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What are some unusual forms of neoplasia?
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1. Epitheliotrophic lymphoma
- Widespread - Multiple ulcerative, crusted lesions - Can progress to depigmentation and alopecia 2. SCC - Multiple, ulcerated, erosive crusted lesions - Frequent secondary bacterial infections |
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How do you diagnose neoplastic nodular skin diseases?
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Cytology
Biopsy |
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Crusting and ulcerated lesions
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Lecture 2
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What are the common crust and/or ulcerated diseases?
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Infectious
- Secondary bacterial (superficial or deep) - Demodex - Viral Immune mediated - Pemphigus foliaceus --> crusted - Lupus (discoid/systemic) --> ulcerated - Vasculitis (ulcerated or alopecic) |
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How do you diagnose viral crusting?
Which virus is common in causing these lesions in cats? DDx? Management? |
Diagnosis
- Clinical lesions (vesicles, ulceration, crusting, multi-focal, well-demarcated) - Histopath (if lesion not classical) Herpes is common DDx - Mosi bite hypersens - AD - ADF Management - Famciclovir |
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Discuss pemphigus foliaceus.
Aetiology? Historical clues Clinical lesions Forms Prognosis |
- Ab mediated attack on desmosomes in stratum corneum (and basal cell layer for PE)
- Drug associated (cephalexin) - History of chronic skin disease Rare, but most common immune meadited skin disease Historical clues - Breed predisposition - Lesion (looks like SBP, but doesn't respond to antis) - Sites (footpads, nasal planum) - No pruritis... may be some in occassional cases Clinical lesions Primary - Pustules, transient - Depigementation (noses, lips, margins) Secondary - Crusts more common - Ulceration less common Forms - Localised (face, nasal planum, footpads) - Localised progressing to generalised - Fulminant generalised disease from onset - Pemphigus erythematosus (localised to face) Prognosis - PF (guarded) - PE (manageable) |
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Discuss Discoid Lupus Erythematosus
Aetiology? Historical clues? Clinical lesions? Prognosis? |
Aetiology
- Ab mediated attack on basal cell layer of ep Historical clues - Breed - Lesions - Sites localised to face, nasal planum, periocular and lips - Uncommon in dogs, rare in cats Clinical lesions - Deep adherent crusting, erosions and ulcerations - May start with subtle depigmentation - Only affects face Prognosis - Fair (relatively easy to manage... can be severe) |
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Discuss systemic lupus erythematosus
Aetiology Clinical lesions |
Aetiology
- Ab mediated attack on BM of epidermis and other organs - No clear breed predispositions - Incidence - VERY RARE Clinical lesions - Very variable (depends on organs affected) - Skin (normal-severe ulceration) - Signs of joint, kidney, haematopoietic or other organ disease may predominate - Great impersonator |
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Discuss vasculitis
Aetiology Clinical lesions |
Aetiology
- Immune mediated attack on endothelial cell walls - Can be smll or lge vessels - Can be neutrophilic, lymphocytic or eosinophilic - Variable immune dysfunction (type 1, type 2) - Triggers (drugs, hypersensitivities, infectious agents) - Uncommon Clinical lesions - Variable - Acute severe disease: sloughing of skin, ulceration - Sub-acute: purpuric lesions - Chronic: alopecia - Localised, regional or generalised |
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How do you diagnose immune mediated diseases?
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Cytology
- PF and PE you see acontholytic cells Histopath ESSENTIAL - if secondary infections, treat prior to biopsies - Search for primary lesions |
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When should you suspect immune mediated diseases?
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Lesions
- Unusual types (depigmentation, purpuric) - Unusual sites (noses, footpads, pinnae) - Crusting/ulcerative unresponsive and cytology not indicating infection Histopath ESSENTIAL |
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How do you treat immune medaited diseases?
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PF, some DLE and PE, SLE
- Immunosuppression - COmmitted owners - Careful monitoring - $$$ - Use high initial dose, then gradual reduction - Consider referral... - Glucocorticoids - Azathioprine - Chlorambucil - Tetracycline/Niacinamide combination - Pentoxifylline Topical options for DLE, PE, PF - Tacrolimus or pimecrolimus - Potent glucocorticoid lotions |
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Ear Disease
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Lecture 3
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What is the pathophysiology of ear disease?
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1. Predisposing factors (breed)
2. Primary causes (underyling diseases) 3. Secondary causes (bacteria, yeast) 4. Perpetuating factors (chronic changes) |
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What are some predisposing factors for ear disease?
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1. Ear type (long vs short, hairy canals)
2. Climate (humidity, high temp) 3. Environmental (frequent swimming?) 4. Nasopharyngeal polyps (cats) 5. Neoplasia |
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What are the primary causes?
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FBs (grass seeds)
Parasites (ear mites --> otodectes cynotis) Hypersensitivities (MOST IMPORTANT) (atopy, food, contact) Endocrine diseases (hypoT) Keratinisation disorders Other |
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What are some secondary causes?
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Bacteria
- Staph intermedius - Pseudomonas - Proteus - E coli - Klebsiella Yeast - Malassezia |
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Discuss the perpetuating factors.
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Chronic inflamm
- Epidermal hyperplasia, hyperkeratosis - Dermal oedema, fibrosis - Ceruminal gland hyperplasia - Calcification - TYmpanic membrane alterations - Otitis media |
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What are some physical findings or ear diseases?
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Otitis externa
- Sore ear (head shaking, ear scratching, drooping, redness, discharge, odour) - Dermatitis surrounding skin, pinnae Otitis media - Head tilt - Painful ear - Facial nerve deficits - Horner's syndrome |
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How do you treat acute disease?
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1. History and clinical signs (primary factors)
2. Cytology (every patient!!) - Sample and assess canal 3. Otoscopic exam (if possible) - FBs, ear mites 4. Treat seocndary bacterial/yeast infections Antimicroboals - Best guided by cytology - Bacterial culture may be helpful (in 5% of cases) - Systemic rarely needed - Topical most effective, 3 weeks minimum Ear cleaners (rarely used) Anti-inflammatories - Important - Topical (hard to avoid) - Systemic (prednisolone) |
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Discuss ear mites
What is it? Clinical signs Diagnosis Treatment |
What is it?
- Otodectes cynotis - large white mites - characteristic coffee ground discharge Clinical signs - variable pruritis - occasionally generalised dermatitis Diagnosis - Otoscopic exam (can see them) - Microscopic exam (mix with paraffin oil, cover slip) - Treatment trial in adult cats Treatment (antiparasitic) - Topical (pyrethrin) - Systemic (ivermectin) - As for other contagious mites (treat all in-contact animals, some may be asymptomatic, young may be more susceptible) |
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How do you treat acute disease of ear mites?
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- Choose your drug based on cytology
- Make sure you choose the right method of administration and volume of drug - Montior their cytology for 2 weeks |
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How do you treat chronic cases of ear mites?
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Same as acute disease PLUS
- Flush (under GA) if copious/persistent discharge - Treat secondary infections aggressively (bacterial culture MAY be helpful, systemic antimicrobials more often) - Anti-inflammatories essential (topicals often sufficient) - Sustained treatment and repeat cytology VITAL (twice weekly for minimum of 6-8 weeks) - Investigate for underlying disease (hypersens, endocrinopathies etc.) Minimise recurrences - Manage primary predisposing factors (swimming? hair removal?) - Regular cleaning - Pulse treatment (if atopic dermatitis involved... anti-inflamm drops 1-2 times weekly) Surgery - Lateral ear resections only with mass or conformational defect in horizontal canals - Bulla osteotomy (drainage of middle ear) - Total ear canal ablation (salvage procedure... usually with poor owner compliance/inability to topically medicate) |
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OTHER causes of crusted and/or ulcerated skin diseases
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Lecture 4
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What are the 'other causes' or ulcerated skin diseases?
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Metabolic epidermal necrosis
Zinc responsive dermatosis |
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Discuss metabolic epidermal necrosis.
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What is it?
- It is a hepatocutaneous syndrome - It's related to liver or pancreatic disease - Poorly understood pathogenesis |
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Discuss zine responsive dermatosis
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Adult form
- Defect in Zn metabolism/absorption - Breed predisposition Rapidly growing puppies - On HIGH Ca diets - Reversible :-) |
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When should you perform a skin biopsy?
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If skin scraping and cytology are normal are you have:
1. Unusual/striking lesions (immune mediated?) 2. Unexplained lesions (exclude common differentials first) 3. Poorly responsive lesions (if diagnosis not determined) 4. If neoplasia possible |
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When should you NOT perform a skin biopsy?
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If you suspect allergies or sarcoptes
If yeast or bacterial infection present (mask underlying primary pathology) |
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Why would you perform a skin biopsy?
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- For histopath usually
- For bacterial culture and sensitivity (deep infections) - For fungal culture/sensitivity (unusual infections) |
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Where can you perform skin biopsies?
How many samples? |
Range of lesions
- Primary (pustules and papules) - Secondary (crusts, alopecia, hyperpigmentation, scaling) How many samples? - 4 samples min... ideally 6-8 |
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What miscellaneous diseases of the skin exist?
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Acne
Feline plasma cell pododermatitis Canine lupoid onychodystrophy |
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Discuss acne
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Common on cat chins
Common on dog muzzles Follicles become dilated, keratin filled and there may be a secondary bacterial/yeast infection Treatment - Topical cleansing - Antibacterials - Follicle flushers |
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Discuss feline plasma cell pododermatitis
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- Soft, enlarged, painful pads
- Aetiology unknown - Many respond to DOXY (for 3-8weeks) |
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Discuss canine lupoid onychodystrophy
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Idiopathic
Abnormal claw growth (brittle, twisted, scaling claws) Sloughed nails DDx - Bacterial or fungal claw infection Treatment - Fatty acids - Doxy - Prednisolone |
